Lately, my otherwise problem free new 15 inch Aluminum PowerBook has been acting a bit strange. Occasionally, when I close the lid to put it to sleep, it won't wake up properly. When I open the lid again, the screen remains off, I can hear an extremely faint whirring sound of some type coming from inside, not loud enough to be the fan, and maybe not even the HD. I've tried the brightness controls, as well as using keystrokes, mouse (built-in and USB) clicks, and clicking the power button to bring it back. It wouldn't accept a CD, and closing the lid again did not produce a comforting thrum of the white light although the whirring stops. The only way to bring it back is to hold down the power button until the whirring stops, (obviously force killing it) and then starting back up again. It starts up no problems then. I have not really found any pattern in the problem and it is somewhat infrequent. The only thing I can figure is that it generally only happens when I am moving around more and closing and opening the lid more frequently. Is there any other knowledge I can arm myself with before I call AppleCare?